Enhanced antibody half-life improves in vivo activity

Area of Science:

• Immunology
• Pharmacology
• Oncology

Background:

• Improved neonatal Fc receptor (FcRn) affinity is known to extend antibody half-life.
• The link between extended half-life and enhanced therapeutic efficacy remains unexplored.

Purpose of the Study:

• To investigate if FcRn-mediated half-life extension enhances the therapeutic efficacy of antibodies.
• To determine if antibodies with prolonged half-lives maintain efficacy at extended dosing intervals.

Main Methods:

• Fc-engineered antibodies with enhanced FcRn affinity were developed.
• Half-life was assessed in human FcRn transgenic mice and cynomolgus monkeys.
• Antitumor activity was evaluated in an hFcRn/Rag1(-/-) mouse model.

Main Results:

• Antibody half-lives were extended up to fivefold in mice and threefold in monkeys.
• Prolonged antibody exposure due to FcRn-mediated enhancement significantly improved antitumor activity.
• Fc-engineered antibodies demonstrated sustained efficacy at longer dosing intervals.

Conclusions:

• FcRn-mediated half-life extension can significantly enhance the therapeutic efficacy of antibodies.
• This approach successfully bridges the need for dosing convenience with the clinical requirement for sustained efficacy.
• Fc-engineered antibodies represent a promising strategy for improved cancer therapy.